Chain of Truth

Curse 5 (The curse price must be paid with life in addition to the card's mana cost before casting the spell.)
Chain of Truth may only be attached to a target nontoken creature.
Whenever enchanted creature attacks another creature, plainswalker or player, it will take that much damage in addition to defending damage.
Whenever enchanted creature takes damage, the damage is also inflicted onto the attacking creature, plainswalker or casting player if the source was an instant, an enchantement or a sorcer